Obs. : 2012-11-16 Planet Ly alpha (photons/cm^2/sec) Mercury 4.027e+11 Venus 3.892e+11 Earth 4.482e+11 Mars 4.223e+11 Jupiter 4.482e+11 Saturn 3.954e+11 Uranus 4.560e+11 Neptune 4.469e+11 Pluto 4.223e+11